The world of transportation is an industry where there is a continued requirement for more advanced and improved developments and where composites are playing an ever-greater role. Trains, buses and cars are now using new materials and adhesion to replace standard soldering or fastening solutions. Locomotives now have outsides panels made of polyester GRP bonded onto the chassis and the car body structures.
The advantages of using adhesives are numerous and well documented. Bonding allows the assembly of dissimilar materials and higher weight loads to be carried as well as improving the uniform distribution of strain and stresses across bonded joints.Adhesives also maintain the integrity and strength of the material or composite as there is no hole, rivet or fastening elements to weaken the structure.No bolts, nuts or screws are necessary and so there is no detraction from the beauty of the finished piece, allowing wider design and aesthetic possibilities.
Adhesives and syntactics solutions in the Aerospace industry
To meet the needs of a changing market, Huntsman Advanced Materials has developed innovative solutions and high performance materials for the fabrication, assembly and repair of interior and exterior aircraft components.
Araldite and Epocast epoxy syntactics, together with pre-cured Eposert syntactic provide solutions for edge sealing, forming and bonding of honeycomb, potting of metallic and plastic inserts and for honeycomb reinforcement and repairs.
Huntsman is continuously developing its epoxy adhesives and syntactics ranges to meet the requirements of fast assembly, weight reduction, REACH compliance and safety, as the fire resistance regulations in aerospace become more stringent.
Epoxy syntactics are produced in a wide range of densities to meet specific handling and performance requirements.The majority of these materials are self-extinguishing and feature easy-to-apply viscosities, sag-resistance and high strength.
Epocast 1645 FR is a new ultra-low density syntactic that meets FAR 25.853a flammability requirements for honeycomb void and edge filling. The new low density syntactic Epocast 1622 FST A/B, available in Semkit, is suitable for various applications including potting of fasteners and honeycomb reinforcement.
To comply with new fire resistance regulations, Epibond 8000 FR epoxy adhesive is designed to enhance fire performance in bonding applications requiring high mechanical performance. For metal and composite bonding, honeycomb or insert potting applications, this new epoxy adhesive meets the flammability, smoke density and toxicity requirements of FAR 25.853 and is available in cartridges for ease of application.
Structural adhesives in the rail industry
Huntsman offers four main types of structural adhesives for all segments of the rail market – from high-speed trains, mainline, regional, metro, suburban and freight trains, as well as the infrastructure around them.
These all have a different chemistry with different structures and physical characteristics that make them suitable for targeted applications and specific processing requirements.
The key features of Huntsman's epoxy, polyurethane, methacrylate and phenolic-based adhesive systems are as follows:
• Epoxy adhesives offer excellent adhesion to metals and thermoset composites, providing excellent durability, chemical and temperature resistance (up to 190°C) with low shrinkage
• Polyurethanes are more suitable for bonding thermoplastics, offering good long-term durability, strength and flexibility
• Methacrylates offer good adhesion on metals, thermoset composites and most thermoplastics, providing both rigid and flexible mechanical properties and minimum surface preparation requirements
• Phenolics are well suited to metals and friction materials.They offer outstanding temperature and chemical resistance, ease of application and a virtually infinite open time once applied
With the products ever evolving, the composite bonders, Araldite AW 4858 / Hardener HW 4858 and Araldite AW 4859 / Hardener HW 4859 were added to Huntsman's range of adhesives.Both systems support long-term durability, offering excellent toughness in combination with high strength.Araldite AW 4859 / Hardener HW 4859 has the added benefit of being suited to environments exposed to high temperatures without any significant changes to its toughened properties.
For structural parts such as roofs, doors, floors and semi-structural products such as floor coverings, seat to floor attachments, door frames and hinges, Araldite AW 4858 / HW 4858 is an example of an epoxy adhesive which offers the advantages of ease of application, high strength and shock resistance on multi-material assemblies
In Italy for example, this adhesive is being used to bond a simple overlap joint aluminium seat fixture within a high-speed train.In this instance, Araldite AW 4858 / HW 4858 was selected for its excellent dynamic load and fatigue resistance.
Araldite AW 4858 / HW 4858 also offers excellent chemical resistance and thermal stability, making it particularly beneficial for exterior applications on carriages where it helps to reduce structural weight whilst improving fatigue resistance on metal assemblies.
With their high strength, impact resistance and outstanding combination of high lap shear and peel strength, these epoxy adhesives are the type of adhesive most commonly used in this example.
The automotive industry is the world's largest user of robotics and it needs adhesives that can cope with the stress of rotational speed of the tool, axial load to the tool and loading time - there is no additional peripheral equipment.
Where strength and durability is required for a range of applications and multiple types of materials, Araldite 2048 and Araldite F348 provide good examples of methacrylate systems from Huntsman that fulfil this need.
These methacrylate adhesives exhibit some of the highest lap shear strengths available (24 MPa on aluminium), along with high elongation, making them ideal for dynamic loading.These benefits are offered in combination with good chemical resistance, low ionic content (for electronic applications) and ease of application.
As with Huntsman's other methacrylate adhesive systems, using Araldite 2048 or Araldite F348 involves minimal surface preparation along with fast setting on many different substrates, thus helping to reduce costs and speed up production.
Araldite 2048 and Araldite F348 demonstrate that it's now possible to achieve excellent bonding between different materials whilst managing structural and weight issues within the design concept.
In 2014, Huntsman was selected by Norma Auto Concept Engineering to bond the components of a rear wing for a prototype sports car.
Founded in 1984 by Norbert Santos and Marc Doucet, whose names make up the brand name 'Norma' Auto Concept Engineering, the French-based business manufactures prototype vehicles for a range of racing. Offering a complete solution to effectively assemble the different substrates that form the wing structure, Araldite 2048 was used to join the aluminium pieces together and Araldite 2031 joins the composites together and to the aluminium parts.
Providing excellent adhesion on a wide range of materials such as metals and thermoset composites, the epoxy adhesive Araldite 2031 delivers superior structural stability and flexibility to the application, along with gap filling properties that fulfil essential performance criteria in offering exceptional resistance to vibration.
The methacrylate adhesive, Araldite 2048, adds to the quality of the application by providing high elongation and one of the highest lap shear strengths available, ensuring the effective management of dynamic loads.
Other benefits Araldite 2048 brought to this application included good chemical resistance, ease of application and extremely high impact resistance.
Marine industry
The increasing demands for high performance materials and sophisticated rapid production technologies in marine applications, similar to those used in the automotive industry, have been a key factor in the development of a new range of products from Huntsman Advanced Materials specifically designed to meet critical marine modelling and prototyping challenges.
Araldite 2015 is a two-component epoxy adhesive paste that cures at room temperature. The designers found this adhesive superior to other formulations in providing better reactivity, efficiency and overall quality of design. While offering high resistance to water, humidity and chemicals, Araldite 2015 also delivers improved performance on the water.
A tough and resilient paste Araldite 2015 is ideal for use on thermoset composites of all types, particularly on fiberglass-reinforced epoxies. The thixotropic, gap-filling adhesive can be applied up to a 10mm thickness. It has a 35 minute gel time and attains handling strength after only four hours at room temperature. Once cured, Araldite 2015 produces joints with high shear strength, good peel strength and good resistance to chemicals, heat, water and impact.
One of the world's most luxurious motor cruiser projects used structural bonding technology from Huntsman Advanced Materials. Araldite® 2015 has been exclusively specified in the construction of the Neptys First Life 27 – a high tech, semi rigid powerboat, made from a vinyl ester infusion.
Easy to mix, Araldite 2015's work life proved appropriate for the necessary timescales the designer had set for bonding the deck to the hull, including the internal components. Particularly important in the decision making process was the need for medium time bonding application, low price and less odour during application and polymerisation.
Because of its short length of 8.5m and speed (50 knots plus), the Neptys First Life 27 is subject to impact and vibrations. As a result, the designers had to be sure that the bonding characteristics of the adhesive combination selected could withstand the stress of the environmental conditions at sea. For this high tech boat, a technical and strong solution was needed. Araldite 2015 allowed the Neptys First Life 27 to withstand the impact of speeds up to 99km/hr.
Emphasis was placed on identifying a formulation capable of providing reactivity for the materials used in the boat's construction. Huntsman produced a comprehensive technical report, including material samples and photos, recommending the use of Araldite 2015 based on its ability to meet the performance characteristics necessary for this type of marine application.
Core range
The Araldite adhesives core range & 2000+ range will continuously be updated to meet the newest demands of innovative design using the bonding technology.
Huntsman Advanced Material is a global manufacturer and marketer of differentiated chemicals.Its operating companies manufacture products for a variety of industries, with the transport sector always a high priority because of its global status and its importance in the infrastructure of developed and developing nations.
